Mobile Data Buttons Disappearing on Samsung Devices

A new bug in Android Lollipop has been going around recently, and this time it causes the mobile data icon to simply vanish from the Quick Settings toggles, particularly on Samsung devices running Samsung’s TouchWiz ROM. According to a user on Android Central, the bug is caused by an update to the Samsung Text-to-Speech engine that was pushed recently.
How a text-to-speech engine can cause the bug is unknown, but Samsung users are adviced to perform these few workarounds for the time being:

Manually go to the Data Usage screen in the Settings app to enable/disable mobile data.

Add a home screen widget to enable/disable mobile data.

Uninstall the Text-to-Speech updates, or disable the engine completely (not confirmed to be working).

Samsung should be pushing out an update to fix this soon, as the bug has already been reported. Should OEMs thoroughly test their updates before pushing them then? Let me know what you think in the comments!